Surveyor's compass

Object/Artifact

-

Historic Hudson Valley

Name/Title

Surveyor's compass

Entry/Object ID

VC.83.4 a-e

Description

a. Compass tripod: wooden with brass hardware, three legged, legs taper to a point. Central triangular pendant suspended by cotton cord, ball in socket allows top to swivel. b-e. Rectangular wooden box holds compass with round face, face has compass points, fleur de lis motif at top of face, box has long crack on top and hole in bottom through which back of compass fits, box also holds two brackets for securing compass to top.

Made/Created

Artist Information

Artist

Alexander Megarey

Attribution

Maker

Date made

circa 1800

Other Names and Numbers

Other Numbers

VC.83.4 A-E
VC.83.4
VC.83.4 a-d

Dimensions

Dimension Description

box

Height

3-1/2 in

Width

14-1/2 in

Depth

7-1/4 in

Dimension Notes

Display Dimensions: 3 1/2 x 14 1/2 x 7 1/4 in. (8.9 x 36.8 x 18.4 cm)

Dimension Description

compass

Height

13-3/4 in

Width

5-7/8 in

Depth

3-1/4 in

Dimension Notes

Display Dimensions: 13 3/4 x 5 7/8 x 3 1/4 in. (34.9 x 14.9 x 8.3 cm)

Dimension Description

tripod

Height

61-1/2 in

Dimension Notes

Display Dimensions: 61 1/2 in. (156.2 cm)

Material

oak, Cotton, Metal, Glass, brass

Condition

Notes

Remarks: Details of condition: (1/29/02) crack in lid.

General Notes

Note Type

Curatorial Remarks

Note

This compass is a vernier, or "Rittenhouse" compass, as described earlier. It remained the common compass of early nineteenth-century America until the surveyor's transit was developed in the 1830s and subsequently became widely adopted. In the field the compass is supported by a tripod with a ball and socket attachment allowing free movement of the compass. The use of a tripod instead of the jacob's staff, a single rod on which a compass was mounted, was first discussed in 1579 by a French instrument maker, Philip Danfrie. It received its first treatment in English in Arthur Hopton's Speculum Topographicum; or the Topographicall Glasses, 1611. The tripod is particularly important when used in conjunction with a second French invention, the spirit level. Melchisedech Thevenot developed the spirit level in 1666 although it did not come into general use on surveying equipment until the 18th century. By the 19th century it is common to find two spirit levels on the surveyor's compass, although their placement varies from instrument to instrument. The combination of the tripod with ball and socket mount and the spirit bubble level enabled surveyors to establish the horizontal plane when setting up their instruments.

Note Type

StorageNote

Note

Home Location: Historic Hudson Valley, Van Cortlandt Manor, Old Parlour